diff --git a/api/mraa/uart.hpp b/api/mraa/uart.hpp
index 9099d5b..cc485a3 100644
--- a/api/mraa/uart.hpp
+++ b/api/mraa/uart.hpp
@@ -28,6 +28,7 @@
 
 #include "uart.h"
 #include "types.hpp"
+#include <stdlib.h>
 #include <stdexcept>
 #include <cstring>